It is known to form a cross-sectional profile of a tubular member by a hydro-forming process in which a fluid filled tubular blank is placed within a die and then the die is closed so that the tubular blank is formed within the die. Fluid pressure is then increased inside the tubular member to expand the blank outwardly against the die cavity to provide a tubular component having a die formed cross-sectional profile. The tubular component may also have different cross-sectional profiles along the length thereof.
For an automotive component such as a fuel filler neck or manifold of a fuel fill system, the fuel filler neck and manifold are made with several pieces of deep drawn stampings and brazed together to form a leak-free tubular member of varying cross-section. This process results in a seam to be added so that the deep drawn stamping process could be used. However, the above-described hydro-forming process could not be used for the fuel filler neck and manifold because of the expansion requirements of the manifold sections.
As a result, it is desirable to provide a new method of hydro-forming a tubular member. It is also desirable to provide a method of hydro-forming a tubular member that allows smaller diameter tubes to be expanded significantly. It is further desirable to provide a method of hydro-forming a fuel filler neck or a fuel neck and manifold as one-piece. Therefore, there is a need in the art to provide a method of hydro-forming a tubular member that meets these desires.